One example of a train management system is the Lockheed Martin Advanced Train Management System (ATMS) that uses on-train processing and advanced digital communications to keep track of and manage the location and speeds of trains on a railway. This permits railroads to increase capacity by reducing distance between trains and increase reliability through better on-time performance. In addition, safety is increased through authority and speed limit enforcement.
The ATMS uses a track database containing a variety of data including geographical coordinates of a number of trackside features that are disposed along the railway tracks as well as a unique identifier for each of the trackside features. The track database is used to create a virtual model of the track in the control system of the train.
Track databases have many components that are constructed by a team of surveyors, software operators, database administrators, and other staff, and are distributed by radio links to trains from central data servers. However, the track database can have errors. The track line's 3-D trajectory can have errors (location/curvature/heading/grade), which can degrade the ability to accurately compute offset into track segment. In addition, errors in feature-coordinate assignments can result in erroneous visual presentation of upcoming trackside features and track line characteristics to train crew and can have several unintended consequences. For example, errors in content can result in erroneously determining train's track occupancy (parallel track), computing actual location along a track, affecting braking enforcement distance calculations, and miss-identifying physical features used in authority limits.
Physical trackside features such as kilometer posts, turnouts, speed limits, passenger platforms, division boundaries, yard limits, etc. are used for two-way traffic management and speed management. However, these trackside features can have errors in their partition offsets which results in track database content errors. In addition, trackside features such as kilometer posts and control points can be unintentionally swapped along the track line (for example kilometer post 130 is actually 129 and vice versa). For this example, an authority issued between kilometer posts 135 and 130 on single track could cause an unintentional physical conflict with an opposing train travelling in the opposite direction, as their movement authorities are generated and deconflicted by km post value by a train dispatcher/controller, not by geographic coordinates.